Retroperitoneal schwannoma: an atypical presentation.

Schwannoma is a rare tumour arising from Schwann cells in myelinated neural sheath of the nerves. They can arise in various places like head, neck, extremities, adrenal, retro peritoneum, psoas muscle. We here present a case of 33-year-old male who came with features of acute pancreatitis, with incidentally detected mass in presacral region on ultrasonography. Investigations like CECT and MRI were suggestive of neurofibroma, radical excision of the mass was done which showed solitary encapsulated tumour and cut sections showed areas of necrosis, and histopathologically it was proven as schwannoma. Most of the schwannoma's are benign, but rarely malignant transformation can occur. It can be associated with von Recklinghausen disease. Benign tumours have excellent prognosis, malignant tumours can present at later date with metastasis after excision also. Radiology plays a key role in diagnosis and follows up. Treatment is radical excision of tumour; recurrence is most common and has to be carefully followed up.